The Lake Peigneur accident was caused by drilling in a salt mine beneath the shallow (10 feet deep) lake. The drill accidentally pierced the third level of the mine causing the lake to drain into the hole. This resulted in the expanding of the hole as soil and salt were washed into the mine by the rushing water, filling the enormous caverns left by the removal of salt over the years. The resultant whirlpool sucked in the drilling platform, eleven barges, many trees and 65 acres (260,000 m2) o... Continue reading ...